diff --git a/src/Forms/GridField/GridFieldConfig_BlogPost.php b/src/Forms/GridField/GridFieldConfig_BlogPost.php
index ccc5de6..74d4a36 100644
--- a/src/Forms/GridField/GridFieldConfig_BlogPost.php
+++ b/src/Forms/GridField/GridFieldConfig_BlogPost.php
@@ -19,7 +19,7 @@ class GridFieldConfig_BlogPost extends GridFieldConfig_Lumberjack
     {
         parent::__construct($itemsPerPage);
 
-        $this->removeComponentsByType('GridFieldSiteTreeState');
+        $this->removeComponentsByType('SilverStripe\\Lumberjack\\Forms\\GridFieldSiteTreeState');
         $this->addComponent(new GridFieldBlogPostState());
     }
 }
diff --git a/src/Model/BlogFilter.php b/src/Model/BlogFilter.php
index 8896004..48c1c37 100644
--- a/src/Model/BlogFilter.php
+++ b/src/Model/BlogFilter.php
@@ -59,7 +59,7 @@ class BlogFilter extends Lumberjack
      */
     protected function subclassForBlog()
     {
-        return in_array(get_class($this->owner), ClassInfo::subclassesFor(Blog::class));
+        return in_array(get_class($this->owner), ClassInfo::subclassesFor('SilverStripe\\Blog\\Model\\Blog'));
     }
 
     /**